Adenosine tri-phosphate, or ATP, is a molecule manufactured by cells which moves the energy produced by respiration - usually at the mitochondria - to wherever in the cell it is needed, in the form of chemical energy within the molecule.

Each molecule of ATP contains, within its structure, two specific chemical bonds, called phosphate bonds, which, upon breakdown, release large amounts of energy that the cell can use to do its "work" - for example, making other molecules it needs for growth, movement etc.